(1) Field of the Invention
This invention relates to a control device of an absorption type cold and warm water system.
(2) Description of the Prior Art
An absoprtion type cold and warm water system generally comprises generators, a condenser, an evaporator, an absorber and heat exchangers. One type of a drive source for this absorption type cold and warm water system utilizes, as described in Japanese Patent Application Laid-Open No. 87752/81, for example, heat of combustion of gas, kerosene, etc. Another type utilizes solar heat in combination with the heat of combustion of gas, kerosene, etc.
In an absorption type cold and warm water system provided with a drive source of the former type, when cold water is produced, control of the temperature of the cold water is effected by adjusting the heat source in a manner to keep the temperature of the cold water at a predetermined temperature level. In controlling the adjustments of the heat source, on-off control or proportional control is adopted. In the on-off control, heating is started at a time when the temperature of the cold water reaches the uppermost level and heating is stopped at a time when it reaches the lowermost level. In the proportional control, the amount of heat produced by heating is continuously controlled in accordance with the difference between the current temperature of the cold water and the lowermost level of its temperature.
In effecting on-off control or proportional control of the heat source, it has hitherto been usual practice only to effect adjustments of the heat source to keep the temperature of the cold water at a predetermined value. However, in actual practice, the amount of heat produced by heating causes a change in the temperature and concentration of a solution in the generators. This is transmitted through the flow of the solution and causes an absorption action of the solution in the absorber and an evaporation action of a refrigerant in the evaporator to occur, thereby causing the temperature of the cold water to drop. Stated differently, even if heating is stopped when the temperature of the cold water drops, the generators, the absorber and the evaporator constituting an absorption type cold and warm water system possess a very high refrigerating ability and prevent the temperature of the cold water that have dropped from rising again at once.
In an absorption type cold and warm water system provided with a drive source of the latter type, when it is intended to produce cold water, the temperature of the cold water is kept at a predetermined value by starting and stopping the operation of a pump for feeding low temperature warm water heated by solar heat and effecting adjustments of an auxiliary heating source relying on the combustion of fuel, such as kerosene or gas. When the temperature of the cold water drops below the predetermined value as a result of the operation of these heat sources, the heat sources are rendered inoperative. However, the generators, the absorber and the evaporator constituting an absorption type cold and warm water system have such a high refrigerating ability that at this time the amount of heat of a heat medium possessed by the generators, for example, prevent the temperature of the cold water from rising at once.
Moreover, in an absorption type cold and warm water system having the drive source of the latter type, when it is intended to produce warm water, the temperature of the warm water is kept at a predetermined value by starting and stopping the operation of a pump for feeding the warm water heated by solar heat and adjusting a heating source relying on the combustion of fuel, such as kerosene or gas. When the temperature of the warm water rises to a level above the predetermined value, the heat sources are rendered inoperative. However, the generators, the absorber and the evaporator constituting an absorption type cold and warm water system has such a high heating ability that at this time the amount of a heat medium possessed by the generators, for example, prevent the temperature of the warm water from dropping at once.
In fact, such high refrigerating and heating abilities as possessed by an absorption type cold and warm water system as described hereinabove have not hitherto been effectively utilized.